I needed these fuses for my landscape lighting installation. I don't understand why manufacturers are still using "old tech" fuses instead of circuit breakers, but they do. However, these fuses are exceptionally well made and have a DOUBLE ELEMENT. I haven't found any other fuse that has this handy feature. An element is a tensioned spring. The other element is the more standard metal strip. If the spring is compressed, the chain has been overloaded. If the metal strip has melted, it is a short circuit. Helped a lot!